The invention concerns a method and a device for treating by means of an air flow carcasses of slaughtered animals during suspended transport in a slaughterhouse after evisceration and prior to weighing.
In a typical slaughtering process, after stunning, the body of the animals is suspended from a hook passed through the hind legs in a clean area. In this way, the body is transported by means of a conveying system at the ceiling (suspension tracks) through the remaining slaughtering process. During the clean evisceration process, the chest part is split and the viscera removed. The individual separated internal organs accompany the carcass in parallel to the veterinary services where they are examined. Parts that exhibit any signs of a disease are sorted out. Subsequently, the carcass is cut in half at the backbone and chest. The carcass is weighed in order to determine the actual slaughter weight (carcass without blood and viscera) and is then transported into the cooling areas. Directly after slaughter, the normal temperature of the carcass is approximately 37° C. to 40° C. and must be cooled within 24 hours to 7° C.
Cooling is required in order to inhibit growth of bacteria. The carcass is cooled in that, for example, cool air (−20° C. to −30° C.) is blown at it. The surface cools down but in the interior the carcass is still warm. Subsequently, transport into a cooling area takes place in which the environmental temperature is maintained at 5° C. Here, the carcass is stored until the next day so that the inner temperature reaches the required value.
It is conventional to clean the slaughtered animals in an art-specific way. The carcasses of the slaughtered animals must be cleaned during the technological slaughtering process for reasons of hygiene. This technological cleaning process is matched to the specifics of the animal body to be slaughtered. This can be, for example, a simple wet cleaning after skinning, scalding or steaming with subsequent dehairing or bristle removal or feather removal from the animal body. Subsequently, the animals are eviscerated and pass a dripping stretch before being weighed.
The publication DD-B 155 031 discloses a method for lowering the losses of warm mass of slaughtered animal carcasses, in particular of cattle parts, in which the carcass parts of the slaughtered animal, immediately after wet cleaning but prior to weighing, are showered with air of ambient temperature to obtain a dry surface in order to then be chilled.
For carrying out the method, a device is to be used comprising a compartment for carcass parts of slaughtered animals transported in suspension that comprises several jet-like blow openings for air that are directed at a slant toward the bottom and intake channels for one or several axial fans, arranged in a closed air circulation system.
The system has several disadvantages. One reason is apparently that the inventors apparently calculated the price of energy higher than the raw material price of meat. Therefore, the goal is energy reduction. However, considering energy reduction does not take into account that in this way a loss of mass of surface-dry carcasses of slaughtered animals results during cooling.
In the described method, not less but more TBW/ECW/ICW (total body water/extracellular water/intracellular water) escapes so that the balance of the invention is disadvantageous with respect to economics.
Still more important are the hygienic and the thus resulting technical problems with the prior art. On the one hand, the minimal time period in which the animal bodies are passed continuously through the described compartment does not result in a sufficient drying action and, on the other hand, it is hygienically disadvantageous to employ untreated air in a closed circuit by blowing in again the saturated moist air that has been removed from the compartment.
EP 0679335 B1 discloses a cleaning device for slaughtered animal carcasses comprising devices for supply of cleaning liquid that is under pressure; a vacuum source; a vacuum nozzle device; a slaughtered animal carcass cleaning head that can be used and positioned by hand wherein the slaughtered animal carcass cleaning head can be placed onto a surface of the slaughtered animal carcass below a contamination located thereon, the slaughtered animal carcass cleaning head has a cleaning liquid jet in the area of the vacuum opening and the supply of cleaning liquid to the liquid jet is controlled, and devices are provided that position the vacuum opening adjacent to a contamination on a slaughtered animal body in order to remove the contamination therefrom without the slaughtered animal carcass cleaning head getting stuck by suction on the surface of the slaughtered animal carcass. In this connection, a water-containing cleaning liquid at a temperature of at least 72° C. is to be used.
This idea hardly solves the problems; because work is done with a lot of hot water by hand, even more surface water is to be expected in the dripping stretch. This aside, manual removal by suction of the liquid that moreover is undesirably loaded with chemicals is complex and inhibits a high throughput speed.
For keeping constant the temperature and atmospheric conditions in poultry breeding, the publication DE 38 40 782 A1 discloses an incubator with air flow control devices in order to control flow of fresh external air into the incubator and in order to control the air in the interior of the incubator; air conditioning adjustors in order to heat, humidify and recirculate the air in the incubator; as well as control or regulating devices for the air conditioning adjustors in order to monitor the temperature level, the moisture level, and the air circulation in the chamber and in order to control or regulate the air conditioning adjustors and the air flow control devices in such a way that temperature and moisture are maintained at predetermined levels and a predetermined air circulation is maintained. It is not disclosed whether this device is also used in slaughterhouses.
The publication DE 8903228 U1 discloses a fan, preferably a wall fan whose fan wheel is arranged in a housing provided with an air inlet and an air outlet that has a pollen filter through which the air that is conveyed by the fan wheel can pass. It is not disclosed whether such filters are effective also in case of pathogenic germs.